What is a Combination Air Relief Flush Valve?
Air relief valves are used for just that, relieving a system of air. A misconception in drip irrigation is clogged emitters are caused by debris in the water. Actually, emitters are designed to displace debris in water in the event of contamination. It’s when the initial airflow comes into a system that tumultuous debris is sent through the irrigation lines and can potentially lead to clogging.
The flush aspect of this valve refers to the displacement of debris upon system initialization. When a zone or system is first put under pressure the Flush Valve opens to allow debris to leave the system. The same pressure that opens the diaphragm on a Flush Valve is also used to close the said diaphragm. Very similar to a typical atmospheric globe valve, Flush Valves use a diaphragm to control flow and closure time.